[Epidemiology and physiopathology of chronic venous leg diseases].

Chronic venous disorders of the lower limbs include a wide range of clinical manifestations involving more than one half of the population in the industrial countries. Varicose veins have a multifactorial origin, linked to ageing, environment (life habits, pregnancies...) and heredity. Their development is related to an increased distensibility of the venous wall and to haemodynamic dysfunction secondary to valvular incompetence. Cutaneous trophic changes and leg ulcers are the final result of severe primary varicose disease or post-thrombotic disease. Elder people are mostly concerned. Skin disease results from ambulatory venous hyperpressure due to several types of reflux involving superficial, deep and perforator veins. Its development is linked to a cutaneous microangiopathy, the central element of which is a decreased capillary density. Venous symptoms are quite widespread and women are more concerned than men; they are also of a multifactorial origin, varicose veins being only one of the causative factors. Their pathogenesis remains unclear, involving venous stasis and probably a functional insufficiency of the lymphatic system.